Early cellular telephones included large housings which contained large and heavy batteries and extensive electronic circuitry. As cellular telephones developed over the years, their size has steadily decreased. This has been partly due to the integration of the electronic functions into semiconductor devices such as digital signal processors specifically designed to process the electrical operations of a cellular telephone. In addition, smaller, more powerful batteries have been developed.
In fact, this progression to smaller and smaller cellular telephones now is limited by form and function requirements. That is, because a user must speak into a microphone and listen to sounds from a speaker, prior art cellular telephones are generally at least large enough to extend from a user's ear to near the user's mouth. More specifically, conventional cellular telephones have height of approximately 6 to 10 inches so as to span the distance between a typical user's ear and the user's mouth.
Though cellular telephones have become smaller and smaller, the typical cellular telephone is still larger than a user's pocket. This requires a user to either carry the cellular telephone in a bag or briefcase, or carry the cellular telephone in his hand. Some cellular telephones include clips so that the cellular telephone may be clipped to a user's belt or pocket. However, these methods of carrying a cellular telephone are not as convenient as carrying the cellular telephone in the user's pocket. Thus, cellular telephone manufacturers have attempted to make cellular telephones which will fit into a user's pocket.
One of the limiting factors in making cellular telephones smaller is a requirement on the size of the keypad. More specifically, the cellular telephone must have a keypad which is of a sufficient size for a user to easily input alphanumeric data into the telephone. Another limiting factor in making cellular telephones smaller is a requirement on the size of the cellular telephone display. A cellular telephone must generally have a display of a sufficient size so as to allow a user to easily see displayed data.
Recently, cellular telephone manufacturers have developed designs which fit within a users pocket. One pocket-sized conventional cellular telephone is a two piece design. The two-piece conventional cellular telephone is comprised of a main body and a plate which is pivotally connected to the main body. The plate is adapted to extend from the main body so as to channel sound to a microphone located near the bottom of the main body. Due to the need for a full sized keyboard and display, the plate is typically made of thin plastic which partially covers the keyboard and/or the display when the plate is in a retracted position. Such a conventional cellular telephone is prone to damage when the plate is extended away from the main body. In addition, since sound is channeled to the speaker, the sound received by the speaker is often of poor quality, particularly when the user does not speak directly into the plate.
Another prior art cellular telephone design employs a speaker located near the top of the telephone in conjunction with a downwardly extending boom. The boom has a microphone disposed near the end thereof. In order of the cellular telephone to fit into a pocket, and also comply with the size requirements for a keypad and a display, conventional cellular telephone designs locate the boom on one side of the cellular telephone.
When a user places the speaker near one ear, the boom extends down far enough such that microphone is at the same level as the user's mouth. In a conventional cellular telephone, the boom extends vertically from the right side of the telephone such that the end of the boom is close to the user's mouth. As a result, conventional cellular telephones function relatively well when a user is right-handed. However, such a conventional cellular telephone design is unacceptable for both right-handed and left-handed use. Furthermore, most users are accustomed to placing the speaker quite close to their mouth. Thus, the user often must twist and/or turn the telephone to manipulate the microphone closer to his mouth. When the user is left-handed, or in any situation where a user desires to place the telephone against his left ear, the distance between the user's mouth and the end of the boom is too great. In addition to compromising the performance of the cellular telephone, such manipulation is uncomfortable for many users.
What is needed is a cellular telephone which is small enough to fit into a user's pocket and which may be operated comfortably by both right-handed users and left-handed users. In particular, a cellular telephone design which includes an adequately sized display and an adequately sized keypad and which will fit into a user's pocket is needed. The present invention meets the above needs.